1. The bony or cartilaginous framework of the head of vertebrates, made up of the bones of the braincase and face; cranium.
2. Informal. The head, regarded as the seat of thought or intelligence: Use your skull and solve the problem.
3. A death's-head.

[Middle English skulle, probably of Scandinavian origin.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.